Electromagnetic valve unit

ABSTRACT

An electromagnetic valve unit comprises a yoke of magnetic metal. The yoke includes upper and lower walls that are integrally connected by side walls. A slit is provided by the upper wall of the yoke. The slit extends along a longitudinal axis of the yoke between axially opposed ends of the yoke. A plurality of electromagnetic valves are abreast installed in the yoke in such a manner that the yoke constitutes outside magnetic paths of solenoid coils of the valves. Each of the solenoid coils has terminal members projected outward from the yoke through the slit.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates in general to electromagneticvalves and more particularly to the electromagnetic valves of anintegrated type that has a plurality of electromagnetic valvesintegrally installed therein.

[0003] 2. Description of the Related Art

[0004] Hitherto, various electromagnetic valve units have been proposedand put into practical use, particularly in the field of wheeled motorvehicles. One of them is shown in Japanese Utility Model ProvisionalPublication (Jikkaihei) 6-32863.

[0005] For clarifying the task of the invention, the electromagneticvalve unit disclosed in the publication will be briefly described.

[0006] The electromagnetic valve unit of the publication comprisesgenerally a rectangular parallelepiped yoke and a pair ofelectromagnetic valves installed in the yoke. That is, respectivesolenoid coils of the two electromagnetic valves are installed abreastin the yoke, and the yoke has two through openings for mounting thereinrespective valve function parts of the two valves. When each solenoidcoil is energized, a magnetic flux is generated using a part of the yokeas an outside magnetic path. Each solenoid coil has terminal membersprojected sideward therefrom and upon assembly, the terminal members areprojected outward through openings that are formed in a longitudinal endof the yoke.

[0007] Usually, in an antilock brake system of wheeled motor vehicles, aplurality of electromagnetic valves are installed in a common blocktogether with a control board, an electric motor, a fluid pump and theirassociated parts. Nowadays, to achieve a compact construction of theblock, there has been proposed a layout wherein the control board isplaced directly on the abreast arranged electromagnetic valves.

SUMMARY OF THE INVENTION

[0008] However, if such layout is practically employed with theabove-mentioned known electromagnetic valve unit, electric connectionbetween the valve unit and the control board would need inevitably alonger wiring because the terminal members of each solenoid coil areprojected outward from the openings formed in the longitudinal end ofthe yoke, that is, from the openings that are positioned away from thecontrol board. If, for shortening the wiring, the openings of the yokethrough which the terminal members are projected outward are provided inan upper wall of the yoke that is positioned just below the controlboard, the work for assembling the solenoid coils to the yoke becomesdifficult or at least troublesome.

[0009] It is therefore an object of the present invention to provide anelectromagnetic valve unit that is free of the above-mentioneddrawbacks.

[0010] According to the present invention, there is provided anelectromagnetic valve unit which comprises a plurality of solenoid coilswhich are abreast installed in a common yoke having their connectionterminals projected in the same direction, that is, toward a controlboard that is to be directly mounted on the yoke.

[0011] According to a first aspect of the present invention, there isprovided an electromagnetic valve unit which comprises a yoke ofmagnetic metal, the yoke including upper and lower walls that areintegrally connected by side walls; a slit provided by the upper wall ofthe yoke, the slit extending along a longitudinal axis of the yokebetween axially opposed ends of the yoke; and a plurality ofelectromagnetic valves abreast installed in the yoke in such a mannerthat the yoke constitutes outside magnetic paths of solenoid coils ofthe valves, each solenoid coil having terminal members projected outwardfrom the yoke through the slit.

[0012] According to a second aspect of the present invention, there isprovided an electromagnetic valve unit which comprises a yoke ofmagnetic metal, the yoke including upper and lower walls that areintegrally connected by side walls; a slit provided by the upper wall ofthe yoke, the slit extending along a longitudinal axis of the yokebetween axially opposed ends of the yoke; and a plurality ofelectromagnetic valves abreast installed in the yoke in such a mannerthat the yoke constitutes outside magnetic paths of solenoid coils ofthe valves, each solenoid coil having terminal members projected outwardfrom the yoke through the slit, wherein the solenoid coils of theelectromagnetic valves are arranged along the longitudinal axis forminga given number of pairs of the coils along the same.

[0013] According to a third aspect of the present invention, there isprovided an antilock brake system for a wheeled motor vehicle, whichcomprises a fluid line extending between a master cylinder of a brakepedal and brake cylinders of road wheels; and an electromagnetic valveunit arranged in the fluid line to selectively establish open and closethe passage of the fluid line, the electromagnetic valve unit comprisinga yoke of magnetic metal, the yoke including upper and lower walls thatare integrally connected by side walls; a slit provided by the upperwall of the yoke, the slit extending along a longitudinal axis of theyoke between axially opposed ends of the yoke; and a plurality ofelectromagnetic valves abreast installed in the yoke in such a mannerthat the yoke constitutes outside magnetic paths of solenoid coils ofthe valves, each solenoid coil having terminal members projected outwardfrom the yoke through the slit.

BRIEF DESCRIPTION OF THE DRAWIGNS

[0014] Other objects and advantages of the present invention will becomeapparent from the following description when taken in conjunction withthe accompanying drawings, in which:

[0015]FIG. 1 is a perspective view of an electromagnetic valve unitwhich is a first embodiment of the present invention;

[0016]FIG. 2 is an enlarged sectional view of the electromagnetic valveunit of the first embodiment;

[0017]FIG. 3 is a front perspective view of a common yoke used in theelectromagnetic valve unit of the first embodiment;

[0018]FIG. 4 is a back perspective view of the common yoke of FIG. 3;

[0019]FIG. 5 is an exploded view of the electromagnetic valve unit ofthe first embodiment;

[0020]FIG. 6 is a front perspective view of a common yoke used in anelectromagnetic valve unit of a second embodiment of the presentinvention;

[0021]FIG. 7 is a back perspective view of the common yoke of FIG. 6;

[0022]FIG. 8 is an exploded view of the electromagnetic valve unit ofthe second embodiment; and

[0023]FIG. 9 is a schematic view of an automotive antilock brake systemto which an electromagnetic valve unit of the present invention ispractically applied.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] In the following, two embodiments 100 and 200 of the presentinvention will be described in detail with reference to the accompanyingdrawings.

[0025] For ease of description, various directional terms, such as,right, left, upper, lower, rightward and the like are used in thefollowing description. However, such terms are to be understood withrespect to only drawing or drawings on which the corresponding part orportion is shown.

[0026] Referring to FIGS. 1 to 5, particularly FIGS. 1 and 5, there isshown an electromagnetic valve unit 100 that is the first embodiment ofthe present invention.

[0027] Electromagnetic valve unit 100 shown by the drawings is of a typethat is installed in an automotive antilock brake system for controllingopening/closing of a fluid passage of the system. That is, the unit 100is integrally installed in a block together with a control board, anelectric motor, a fluid pump and their associated parts. Although notshown in the drawings, the control board is placed directly aboveelectromagnetic valve unit 100.

[0028] As is best seen from FIG. 5, in this first embodiment 100, eightelectromagnetic valves 2 are installed in a common yoke 3. Morespecifically, four pairs of electromagnetic valves 2 are abreastarranged in common yoke 3 in order.

[0029]FIG. 2 shows in a sectional manner the paired valves 2. Althoughthese paired valves 2 have a slight difference in construction, theirbasic structures are generally the same. However, the left valve 2 is ofa normally closed type and the right valve 2 is of a normally open type.

[0030] Each electromagnetic valve 2 generally comprises, in addition tothe common yoke 3, a solenoid coil 4 and a valve function part 5, asmain components. Solenoid coil 4 comprises a plastic bobbin 6 and awinding 7 disposed around bobbin 6.

[0031] As is understood from FIGS. 2 and 5, both terminal ends of eachwinding 7 are connected to respective terminal pins 8 and 8 that areembedded in a rectangular projection 30 provided by bobbin 6. That is,each bobbin 6 has at an upper part the rectangular projection 30 throughwhich two terminal pins 8 and 8 are projected upward.

[0032] It is to be noted that the terminal pins 8 and 8 are projectedaxially outward with respect to the corresponding solenoid coil 4.

[0033] As is seen from FIG. 2, valve function part 5 comprises a tubularvalve body 9 and an armature 10 axially movably received in valve body9. A lower end of armature 10 is equipped with a valve member 11 that iscapable of closing a passage defined by a valve seat 12. That is, whenarmature 10 is moved upward, valve member 11 opens the passage and whenarmature 10 is moved downward, valve member 11 closes the passage.

[0034] Tubular valve body 9 is tightly and concentrically received in acenter bore of bobbin 6 of solenoid coil 4 and has a thicker lowerportion 9 a that is snugly put in a bore 14 formed in a metal housing 13of the antilock brake system (ABS). Preferably, housing 13 is made ofaluminum or the like.

[0035] Housing 13 is formed with first and second ports 15 and 16 thatare exposed to the bore 14. That is, in response to the open and closeactions of valve member 11 relative to the passage of valve seat 12, thefluid connection between first and second ports 15 and 16 is establishedand blocked respectively.

[0036] As is mentioned hereinabove, the left valve 2 is of a normallyclosed type. Thus, valve member (or valve ball) 11 is biased by a spring17 in a direction to close the passage of valve seat 12. While, theright valve 2 is of a normally open type, and thus valve member 11 isbiased by a spring 17 in a direction to open the passage of valve seat12.

[0037] Referring to FIGS. 3 and 4, there is clearly shown the commonyoke 3 in a perspective manner. FIGS. 3 and 4 show front and rear viewsof yoke 3, respectively.

[0038] As is understood from FIG. 3, yoke 3 has a generally rectangularparallelepiped shape, that comprises upper and lower walls 18 and 20 andside walls (no numerals) each extending between upper and lower walls 18and 20. That is, yoke 3 has a rectangular cross section when cut in animaginary plane perpendicular to a longitudinal axis of the yoke 3.

[0039] Axially opposed ends of yoke 3 are opened, which are denoted bynumerals 31 and 31 in the drawings.

[0040] As is seen from FIG. 3, upper wall 18 is formed at a middleportion thereof with a longitudinally extending slit 19. As will becomeapparent as the description proceeds, the yoke 3 is a device thatcreates outside magnetic paths. For this purpose, yoke 3 is constructedof a magnetic metal.

[0041] As is seen from FIGS. 1 and 5, within yoke 3, four pairs ofelectromagnetic valves 2 are abreast arranged in order in such a mannerthat the paired solenoid coils 4 of each pair of valves 2 face eachother with respect to an imaginary plane that extends along thelongitudinal axis of yoke 3. More specifically, the paired solenoidcoils 4 of each pair of valves 2 are arranged having slit 19 placedtherebetween.

[0042] As is seen from FIG. 5, when it is intended to assemble unit 100,the paired valves 2 are slid into yoke 3 from both open ends 31 of thesame. In the illustrated embodiment, two pairs are led into yoke 3 fromthe right open end 31, and the other two pairs are led into yoke 3 fromthe left open end 31.

[0043] As is seen from FIG. 1, upon proper arrangement of valves 2 inyoke 3, rectangular projections 30 of the paired solenoid coils 4 of thevalves 2 are neatly put in and projected upward from slit 19. Terminalpins 8 of solenoid coils 4 are thus projected upward as shown.

[0044] As is best seen from FIGS. 1, 2 and 3, upper wall 18 of yoke 3 isformed with eight circular openings 21 and also lower wall 20 of yoke 3is formed with eight circular openings 22 that are aligned with thecorresponding openings 21 to constitute eight pairs of aligned openings21 and 22.

[0045] As is understood from FIGS. 1 and 2, each pair of the alignedopenings 21 and 22 are arranged to install in yoke 3 the valve functionpart 5 of the corresponding electromagnetic valve 2.

[0046] As is seen from FIG. 2, rectangular projection 30 of eachsolenoid coil 4, that slidably contacts the edge of slit 19, can serveas a positioner for positioning the bobbin 6 relative to the alignedopenings 21 and 22.

[0047] That is, as is seen from FIG. 5, each paired valves 2 can slideinto desired positions of yoke 3 by sliding the paired projections 30 inand along slit 19 of yoke 3.

[0048] As is seen from FIGS. 3 and 4, lower wall 20 of yoke 3 is formedat a center area thereof with a circular opening 23 through which a bolt(not shown) passes to secure yoke 3 to housing 13. As is seen from FIG.3, provision of slit 19 of yoke 3 facilitates the work for turning thebolt.

[0049] Furthermore, lower wall 20 is formed at each side area with twoparallel slits 24 that define therebetween a longitudinally extendingstrip 25. The strips 25 are slightly bent outward from yoke 3, so thatupon mounting of yoke 3 on housing 13, the strips 25 are resilientlypressed against housing 13 thereby to assure a tight connection of yoke3 to housing 13.

[0050] As is best seen from FIG. 1, upon proper assembly ofelectromagnetic valve unit 100, all of terminal pins 8 of the unit arepositioned at the upper side of yoke 3. Thus, when a control board (notshown) is brought onto the upper side of yoke 3, the terminal pins 8 canbe automatically inserted into corresponding terminal openings providedin the control board thereby achieving an electric connection betweenthe valve unit 100 and the control board. That is, the terminal openingsare shaped to easily receive the terminal pins 8 and constructed tograsp the pins 8 when the control board is properly received on theupper side of the yoke 3.

[0051] In the following, advantages of electromagnetic valve unit 100will be briefly described in the following.

[0052] First, as has been just mentioned hereinabove, upon putting of acontrol board onto the unit 100, the electric connection between theunit 100 and the control board is automatically and instantly achieved.That is, there is no need of using longer wiring for such connection,unlike in the case of the afore-mentioned publication 6-32862.

[0053] Second, mounting of the plurality of electromagnetic valves 2 inyoke 3 is easily carried out because valves 2 can be inserted into yoke3 from both open ends 31 of yoke 3. During insertion of valves 2, therectangular projections 30 of each paired valves 2 slide along slit 19and thus serve as a guide means for properly positioning the pairedvalves 2 to their proper positions in yoke 3.

[0054] Third, because of provision of the longitudinally extendingstrips 25 that are slightly bent outward from yoke 3, yoke 3 can beresiliently pressed against housing 13 when connected to housing 13through the connecting bolt (not shown). That is, undesired play of yoke3 can be suppressed or at least minimized. The resiliency possessedstrips 25 are easily provided by only providing yoke 3 with parallelslits 24. That is, the resilient pressing of yoke 3 to housing 13 ismade without using separate spring member, which brings about a lowercost production of valve unit 100.

[0055] Fourth, each resiliency possessed strip 25 functions to disruptthe magnetic paths that are produced by the paired solenoid coils 4 thatface each other having the two slits 24 put therebetween. Thus,undesired interference of magnetic flux between the paired solenoidcoils 4 is suppressed or at least minimized, and thus, the valveperformance of each electromagnetic valve 2 is improved.

[0056] Fifth, since the four pairs of valves 2 are abreast installed inyoke 3 in order, the valves 2 (more specifically, the solenoid coils 4of the valves 2) can share the same magnetic path area on yoke 3 withone another. Thus, the magnetic path resistance can be lowered withoutincreasing the thickness of yoke 3.

[0057] In the above-mentioned first embodiment 100, four pairs ofelectromagnetic valves 2 are installed in yoke 3. If the length of yoke3 is increased, more than four pairs can be installed.

[0058] Referring to FIGS. 6 to 8, particularly FIG. 8, there is shown anelectromagnetic valve unit 200 that is a second embodiment of thepresent invention.

[0059] Since the unit 200 is similar to the unit 100 of theafore-mentioned first embodiment, only parts or portions that aredifferent from those of the unit 100 will be described in detail in thefollowing.

[0060] As is understood from FIG. 6, in this second embodiment 200, thecommon yoke 103 is much simpler than yoke 3 of the first embodiment 100.

[0061] That is, as is seen from FIG. 7, yoke 103 has no means orconstruction that corresponds to the longitudinally extending strips 25(see FIG. 4) employed in the first embodiment 100.

[0062] Thus, when it is intended to mount yoke 103 onto housing 13 (seeFIG. 2), a separate spring member (not shown) has to be put between yoke103 and housing 13 so that yoke 103 can be resiliently pressed againsthousing 13.

[0063] Since the basic structure of valve unit 200 is substantiallyidentical to that of valve unit 100 of the first embodiment,substantially same advantages as those of the valve unit 100 except thethird and fourth advantages are also obtained in the valve unit 200 ofthe second embodiment.

[0064] In addition to the advantages just mentioned, the valve unit 200of the second embodiment has the following advantage.

[0065] That is, since lower wall 20 of yoke 103 has no structurecorresponding to the longitudinally extending strips 25 employed in thefirst embodiment 100, the magnetic paths produced by the paired solenoidcoils 4 can constitute continuous paths at lower wall 20.

[0066] Accordingly, as is seen from FIGS. 6 and 7, the magnetic fluxesof solenoid coils 4 installed in yoke 103 are forced to largely extendto a laterally center area of lower wall 20, which means an increase inthe magnetic path section that is practically used by each valve 2 andthus the magnetic path resistance is lowered. Thus, the thickness of thecommon yoke 103 can be further reduced.

[0067] In the following, modifications of the invention will bedescribed.

[0068] In the above-mentioned two embodiments 100 and 200, common yoke 3or 103 that has both ends 31 opened is used. In such yoke 3 or 103,production is easily carried out with press working applied to a metalplate. If desired, a common yoke of a type having only one end openedmay be used in the present invention.

[0069] Furthermore, in the present invention, it is not always necessaryto arrange electromagnetic valves 2 in such a way that these valves 2are installed in yoke 3 or 103 forming several pairs of them entirelyalong the longitudinal axis of yoke 3 or 103. However, if desired,single valve or valves 2 may be arranged in the row of the paired valves2.

[0070] In the disclosed first and second embodiments, electromagneticvalve units 100 and 200 are described as being applied to an automotiveantilock brake system for controlling opening/closing of a fluid passageof the system. Of course, the units 100 and 200 may be applied to othersystems that need controlling opening/closing of a fluid passage.

[0071] Referring to FIG. 9, there is schematically shown an antilockbrake system (ABS) for a wheeled motor vehicle, to which theelectromagnetic valve unit 100 or 200 of the invention is practicallyapplied. As shown, the unit 100 or 200 is arranged in a fluid line 50that extends from a master cylinder 52 of a brake pedal 54 to brakecylinders 56 of road wheels 58 (only one is shown).

[0072] The entire contents of Japanese Patent Application 2003-147182filed May 26, 2003 are incorporated herein by reference.

[0073] Although the invention has been described above with reference tothe embodiment of the invention, the invention is not limited to suchembodiment as described above. Various modifications and variations ofsuch embodiment may be carried out by those skilled in the art, in lightof the above description.

What is claimed is:
 1. An electromagnetic valve unit comprising: a yokeof magnetic metal, the yoke including upper and lower walls that areintegrally connected by side walls; a slit provided by the upper wall ofthe yoke, the slit extending along a longitudinal axis of the yokebetween axially opposed ends of the yoke; and a plurality ofelectromagnetic valves abreast installed in the yoke in such a mannerthat the yoke constitutes outside magnetic paths of solenoid coils ofthe valves, each solenoid coil having terminal members projected outwardfrom the yoke through the slit.
 2. An electromagnetic valve unit asclaimed in claim 1, in which the lower wall of the yoke is integrallyformed with at least one strip that is angled relative to the lowerwall, so that the strip exhibits a resiliency when pressed toward thelower wall.
 3. An electromagnetic valve unit as claimed in claim 2, inwhich the lower wall of the yoke has such a structure as to permitmagnetic paths produced by the solenoid coils to constitute continuouspaths at the lower wall.
 4. An electromagnetic valve unit as claimed inclaim 3, in which the yoke has a generally rectangular cross section andhas longitudinally ends thereof opened.
 5. An electromagnetic valve unitas claimed in claim 3, in which the strip of the yoke is provided byproviding the lower wall of the yoke with parallel slits, the parallelslits defining therebetween the strip.
 6. An electromagnetic valve unitas claimed in claim 2, in which the yoke has a generally rectangularcross section and has longitudinally ends thereof opened.
 7. Anelectromagnetic valve unit as claimed in claim 2, in which the solenoidcoils of the electromagnetic valves are arranged along the longitudinalaxis forming a given number of pairs of the coils along the same.
 8. Anelectromagnetic valve unit as claimed in claim 1, in which the lowerwall of the yoke has such a structure as to permit magnetic pathsproduced by the solenoid coils to constitute continuous paths at thelower wall.
 9. An electromagnetic valve unit as claimed in claim 8, inwhich the yoke has a generally rectangular cross section and haslongitudinally ends thereof opened.
 10. An electromagnetic valve unit asclaimed in claim 8, in which the solenoid coils of the electromagneticvalves are arranged along the longitudinal axis forming a given numberof pairs of the coils along the same.
 11. An electromagnetic valve unitas claimed in claim 1, in which the solenoid coils of theelectromagnetic valves have each a projection that slidably contacts anedge of the slit of upper wall of the yoke.
 12. An electromagnetic valveunit as claimed in claim 2, further comprising a housing of an antilockbrake system, onto which the yoke is tightly mounted having the strip ofthe lower wall of the yoke resiliently put therebetween.
 13. Anelectromagnetic valve unit as claimed in claim 12, in which the housinghas a plurality of bores in which valve function parts of theelectromagnetic valves are partially received respectively, and in whichthe lower wall of the yoke is formed with a plurality of openingsthrough which the valve function parts of the electromagnetic valvespass respectively.
 14. An electromagnetic valve unit comprising: a yokeof magnetic metal, the yoke including upper and lower walls that areintegrally connected by side walls; a slit provided by the upper wall ofthe yoke, the slit extending along a longitudinal axis of the yokebetween axially opposed ends of the yoke; and a plurality ofelectromagnetic valves abreast installed in the yoke in such a mannerthat the yoke constitutes outside magnetic paths of solenoid coils ofthe valves, each solenoid coil having terminal members projected outwardfrom the yoke through the slit, wherein the solenoid coils of theelectromagnetic valves are arranged along the longitudinal axis forminga given number of pairs of the coils along the same.
 15. Anelectromagnetic valve unit as claimed in claim 12, in which the solenoidcoils of the electromagnetic valves have each a projection that slidablycontacts an edge of the slit of the upper wall of the yoke.
 16. Anelectromagnetic valve unit as claimed in claim 13, in which the yoke isrectangular parallelepiped in shape, the yoke has axially opposed endsopened, a slit is provided by the upper wall of the yoke and extendsalong a longitudinal axis of the yoke between the axially opposed endsof the yoke, the electromagnetic valves are installed in the yoke in amanner to form a certain number of pairs thereof, each pair includes twoelectromagnetic valves that are positioned at opposed portions withrespect to an imaginary plane that extends in and along the slit andalong the longitudinal axis of the yoke, each electromagnetic valveincludes a solenoid coil that has terminal pins, and projections areprovided by the solenoid coils of the electromagnetic valvesrespectively, the projections are received in the slit in a manner toform the certain number of pairs thereof, each pair includes twoprojections that are in contact with laterally opposed edges of the slitrespectively, and each projection receives therein the terminal pins ofthe corresponding solenoid coil and has the terminal pins projectedoutward therefrom.
 17. An electromagnetic valve unit as-claimed in claim16, in which each of the electromagnetic valves further comprises: atubular valve body tightly and centrically received in a center bore ofa bobbin of the solenoid coil; an armature axially movably received inthe tubular valve body; a valve member held by the armature to movetherewith; a valve seat to which the valve member is contactable toestablish open/close condition of a fluid passage; and a biasing memberfor biasing the armature in a given direction.
 18. An electromagneticvalve unit as claimed in claim 17, in which the tubular valve body hasan upper portion received in an opening formed in the upper wall of theyoke and a lower portion received in an opening formed in the lower wallof the yoke.
 19. An electromagnetic valve unit as claimed in claim 18,in which the lower portion of the tubular valve body is received in ahousing on which the lower wall of the yoke is mounted.
 20. An antilockbrake system for a wheeled motor vehicle, comprising: a fluid lineextending between a master cylinder of a brake pedal and brake cylindersof road wheels; and an electromagnetic valve unit arranged in the fluidline to selectively establish open and close the passage of the fluidline, the electromagnetic valve unit comprising a yoke of magneticmetal, the yoke including upper and lower walls that are integrallyconnected by side walls; a slit provided by the upper wall of the yoke,the slit extending along a longitudinal axis of the yoke between axiallyopposed ends of the yoke; and a plurality of electromagnetic valvesabreast installed in the yoke in such a manner that the yoke constitutesoutside magnetic paths of solenoid coils of the valves, each solenoidcoil having terminal members projected outward from the yoke through theslit.